1. Field of the Invention
This invention relates to a vehicle upholstery member (hereinafter referred to as "upholstery member") and more particularly to an upholstery member which is capable of exactly protecting passengers (particularly, their hips and waists) in the event of a vehicle collision and which can be manufactured at low costs.
2. Description of the Related Art
In recent years, high safety from not only a head-on collision, but also a side collision has been demanded for vehicles. An attempt is made to provide a sufficient shock absorption capability for upholstery members against which passenger's hips or waists directly strike at a side collision, such as an armrest 81 and a door panel 82 shown in FIG. 9.
For example, as shown in FIG. 10A, an upholstery member E having a pad layer 832 made of a resin foam substance placed on the rear of an outer shell 831 has been proposed in Japanese Utility Model Unexamined Publication Nos. Hei 4-293640 and Hei 5-514. As shown in FIG. 10B, an upholstery member F having a lattice-shaped rib structure 852 placed on the rear of an outer shell 851 has also been used widely.
However, in the former, the upholstery member E is manufactured through various steps such as preliminary forming of the outer shell 831 and foam formation of the pad layer 832, thus has a long manufacturing cycle and is low in productivity and high in manufacturing costs.
On the other hand, for the upholstery member F in the latter, the outer shell 851 and the rib structure 852 can be molded integrally; even if they are manufactured as separate pieces, and they can be assembled comparatively easily. Therefore, the upholstery member F of this kind can be manufactured efficiently and at low costs.
However, in the conventional upholstery member F, the layout, dimensions, thickness, and total balance of the rib pieces 852a and 852b are not necessarily appropriate, thus often the upholstery member F does not provide adequate shock absorption. For example, in the case where the rib pieces 852a are in a state in which they cannot sufficiently buckle, a shock force cannot sufficiently be absorbed and often is transmitted to passengers. In contrast, in the case where the rib pieces 852a are in a state in which they buckle too easily, often deformation develops momentarily and is completed before the shock force can sufficiently be absorbed.
Often the structure of a vehicle door of a car varies depending greatly on the type of car, such as popular, high-grade, lightweight, or large car. Thus, the shock absorption capability of the vehicle door at a side collision also varies from one car to another and the shock force that the upholstery members undergo also vary. Therefore, the advent of upholstery members capable of exactly absorbing a shock force in a wide range of cars has been desired.